fuel system design

[MOTOWN]

What Walbro model number do you have? There are several 400 models. Also, is the unit electric? In tank?

There is only one Walbro 400lph in tank pump that im aware of , yes in tank electric pump.

[FordNut]

Return is so much easier

Yep. I have one of the highest hp Marauders and am still returnless. So to all the naysayers saying it can't be done

Most who have had problems didn't get their tune adjusted properly to compensate for the higher flow pumps.

[FordNut]

But does the FRPS operate correctly with positive manifold pressure? The older return fuel systems would need the regulator swapped out for a pressure-capable unit when forced induction was added.

Mine works fine.

The numbers say a single Aeromotive 340 is sufficient for 600HP using an efficient blower at less than 15psi boost, although not with a great deal of margin. Given the current draw I could see where two pumps might overload the FPDM.

I never tried a single pump. All I can tell you about is what I've actually tried. Twin Cobras, Twin GT supercars, Twin Aeromotive 340s.

And I have never blown a FRPS.

[lifespeed]

Mine works fine.

So you get 58psi in the fuel rails at 15psi boost with the factory FRPS?

[FordNut]

So you get 58psi in the fuel rails at 15psi boost with the factory FRPS?

I'm not sure. Something like that, though. It is referenced to the manifold pressure. When I'm in boost I'm watching the road, not the gauges.

[Lowndex]

I'm not sure. Something like that, though. It is referenced to the manifold pressure. When I'm in boost I'm watching the road, not the gauges.

"When I'm in boost I'm watching the road, not the gauges."
Damn, that what I have been doing wrong in my Smart car.

[Lowndex]

There is only one Walbro 400lph in tank pump that im aware of , yes in tank electric pump.

Cool and thanks. Ordering a second one.

[lifespeed]

Cool and thanks. Ordering a second one.

You sure you need two?

[lifespeed]

I'm not sure. Something like that, though. It is referenced to the manifold pressure. When I'm in boost I'm watching the road, not the gauges.

Yeah, keep your eyes on the road! So long as you confirmed fuel pressure increases with manifold pressure.

I did not want to assume the Ford vacuum-referenced sensor work under boost.

[Lowndex]

You sure you need two?

If I am wrong, you can have the second one.

[Logizyme]

Plenty of eaton-style swaps running 9-15 PSI on the factory FRPS and yes it will maintain a 40PSIG to the manifold.

[RacerX]

You can set the fuel rail pressure in the tune for whatever you want. It doesn't have to be the stock 39.9psi. If you set it higher, the pcm takes care of the injector slopes. I'll still be returnless, using one of my FPDMs and have 620+ to the wheels shortly. I had 520 no probs. After a few more tweaks, even more. It can be done returnless.

[lifespeed]

Plenty of eaton-style swaps running 9-15 PSI on the factory FRPS and yes it will maintain a 40PSIG to the manifold.

Good to know.

[blkZooM]

http://www.svtperformance.com/forums...nd-KB-dual-BAP

http://www.ebay.com/itm/like/2317615...&ul_noapp=true

http://www.vmpperformance.com/Inject...p/injadapt.htm

Keep the stock rails buy you some -8 an fuel lines, fuel filter and fittings from summit racing, modify your fuel hat to run two extra wires for the second pump do the wire upgrade while you are at it and call it a day. Nice "built" fuel system that will make a ton of power. Not sure if you want to run two pumps or not if you aren't add a bap I would guess.

[lifespeed]

Keep the stock rails buy you some -8 an fuel lines, fuel filter and fittings from summit racing, modify your fuel hat to run two extra wires for the second pump do the wire upgrade while you are at it and call it a day. Nice "built" fuel system that will make a ton of power. Not sure if you want to run two pumps or not if you aren't add a bap I would guess.

The math says a large single pump is fine. Although the Walbro 400 has more margin than the Aeromotive 340, either should work for less than 650HP.

I'll probably go with the Walbro just to be sure. My current plan is to use the stock hard lines, rails and a 3" filter. If anything else besides the wire gauge and FPDM needs upgrading I'll do it as needed.